Detachable tooth-facing for bridgework or gold plates.



. No. 777,521. PATENTED DEG.13, 1904.

L I M. L. LEOB.

DETACHABLE TOOTH FACING FOR BRIDGEWORK OR GOLD PLATES.

APPLICATION FILED FEB. 23, 1904.

NITE STATES Patented December 13, 190%.

[PATENT OFFICE.

MILES L. LEOB, OF CLEVELAND, OHIO.

SPECIFICATION forming part of Letters Patent No. 777,521, dated.December 13, 1904.

Application filed February 23, 1904:. Serial No. 19 L971. (No model.)

To (all whom it may concern:

Be it known that I, Minus L. Leon, a citizen of the United States, and aresident oi. lleveland, county of Ouyahoga, State of Ohio, have inventedcertain new and useful Iniprovements in Detachable TlTooth-l acings :lorBridgework or Gold Plates, of which I hereby declare the following to bea full, clear, and exact description, such as will enable others skilledin the art to which it appertains to make and use the same.

The general objects of my invention are to provide means whereby aporcelain tooth-facing can be readily attached and detached from themetal backing and to provide a metal rim for the incisive edge of thetooth, so that the porcelain will be protected and uninjured by the actsof mastication.

The invention consists in a porcelain tooth or facing of porcelain inwhich a dovetailed groove has been cut, and a corresponding dovetailprojection is formed upon the inside of the metal back, adapted toengage with the dovetailed groove in iillG'DOlCGldlH and upon which theporcelain facing can only be fitted in one direction-that is, byapplying the incisive edge of the first to the dovetailed projection.

The invention also consists in the turned edge oi the backing upon whichthe incisive edge of the facing rests.

The invention also consists in the details of construction andcombination and arrangement of minor parts, as hereinafter described,shown in the accompanying drawings, and specifically pointed out in theclaim.

In the accompanying drawings, Figure 1 is a perspective view of a bridgeof six teeth, showing the metal back, where two of the porcelain facingshave been omitted. Fig. 2 is a longitudinal central section through ametal socket, showing the manner of attaching the porcelain facing andfor protecting its incisive edge. Fig. 3 is a similar section throughone of the central plates between the sockets. Fig. 4: is a centraltransverse section through the Fig. 5 is a perspective view of one ofthe central backing-plates before it is inserted in the bridge; and Fig.6 is a perspective view of the inner side or a tooth-facing, showing thedovetail groove cast therein. Fig. 7 shows the adaptation to a molartooth.

In the views, 1 is the porcelain facing, which is beveled away at eachend, the upper edge at 2 to afli'ord room. for the gum and the loweredge at 3 so that the metal backing can approach the incisive edge andprotect the tooth from strain.

a is a dovetail groove longitudinallycast in the back of the facing andextending through the bevel at the lower edge, but not extending throughthe upper or gingival bevel, For the reason that in this manner thesaliva will be prevented from gaining access to the dovetail groove andthecement, by means of which the parts are secured together. The wall at5 therefore serves to protect the groove.

6 is the gold or other metal backing, upon the inner face of which issecured or cast the projecting dovetail 7, which is inserted in thecorresponding groove in the facing. 'llhis projection is provided. withthe shoulder 8 at its upper end, which strikes against the wall at 5 andlimits its movement. The lower edge of the metal backing is turnedoutwardly at 9 to follow the bend of the edge of the porcelain, and theedge of the backing is bent outwardly under the edgeo'f the tooth at 10,thus supporting and protecting it.

It will readily be seen that the Facing can only be placed in positionfrom the upper edge of the backing and when cement or gutta-percha isapplied the facing becomes rigidly attached to the backing withoutdanger of subsequently loosening. The gutta percha can readily beremoved to separate the parts by heating.

The construction is exceedingly effective and simple, cheap in initialcost, and permits of a heavy metal edge protecting the incisive edge ofthe facing.

In Fig. 7 the adaptation of the invention to a molar tooth is shown.Here 11 is the porcelain for the groove and 5 the limiting-wall. Since,however, the porcelain needs no protection on its lower edge, the metalbacking is not continued far beyond the groove, and the protection forthe groove to prevent moisture from entering it can be arranged bycovdovetailed slot in said facing, extending longitudinally of thefacing through thebevel at the incisive end, to'witbin a short distanceof the bevel at the gingival end of the facing, substantially asdescribed. 7

In testimony whereof I herebyset my hand this 10th day of February,1904.

MILES L. LEOB.

WVitnesses: I

GEO. S. COLE, WM. M. MONROE.

